1. Field of the Invention
The present invention relates to a position-recognizing system for a self-moving robot, and more particularly, to a position recognizing system for a self-moving robot capable of accurately recognizing a current location of a robot by detecting an indication previously mounted in a certain position of a floor through a sensor provided at the robot.
2. Description of the Background Art
In general, various research activities on self-moving robots are ongoing according to their use. In the present specification, a robot cleaner, which is most widely used of the self-moving robots, is taken as an example for the convenience of explanation.
A robot cleaner senses a cleaning area and an obstacle by using a sensor by a command of a control unit, and travels the cleaning area, automatically cleaning the area. When power of a battery provided in the device is exhausted, the robot cleaner moves to a charging station which is provided at a predetermined position and is recharged. After the recharging is completed, the robot cleaner returns to its original position and performs cleaning.
Such a conventional robot cleaner senses its location and the cleaning area by using an ultrasonic sensor or a vision system.
As one example, in the Korean Patent 10-1991-0002407, a robot cleaner is disclosed which detects a distance with front, left and right sides through an ultrasonic sensor installed at the front, left and right sides of a vacuum cleaner, moves in zigzags, repeating straight advance-180 degree right turn-straight drive-180 degree left turn, and thusly detects whether there is a place to be cleaned.
As another example, in the Korean Patent(10-1995-0026477), a robot cleaner is disclosed, which measures a distance and a moving angle from a wall of the robot cleaner by an ultrasonic sensor.
As still another example, in the Korean Patent (10-2004-0047371), a robot cleaner is disclosed which avoids an obstacle by capturing the inside of a space to be cleaned using a vision system.
However, if a location of the robot cleaner is controlled by ultrasonic waves or a vision system, an error may occur in measuring a location of the robot cleaner according to a state of a captured surface and a reflection surface where the ultrasonic waves are reflected. Also, even though the accurate location measurement is made, the robot cleaner may accidentally slide according to a state of a floor or may not reach an objective spot due to an unexpected collision with an obstacle.